| Title |
Developing Suspended Sediment Delivery Ratio in the Lake Imha Watershed |
| Authors |
전지홍 ( Ji-Hong Jeon ) ; 최동혁 ( Donghyuk Choi ) ; 김재권 ( Jae-Kwon Kim ) ; 김태동 ( Taedong Kim ) |
| DOI |
https://doi.org/10.15681/KSWE.2017.33.6.744 |
| Keywords |
Calibration; HSPF; Lake Imha; Suspended sediment loads |
| Abstract |
The sediment delivery ratio (SDR) has been used widely to estimate sediment loads by multiplying soil loss through RUSLE. In this study, the SDR equation was developed for the Lake Imha watershed using soil loss calculated by RUSLE and sediment loads by the calibrated HSPF. The ratio of watershed relief and channel length (Rf/Lch), the ratio of watershed relief and watershed length (Rf/Lb), curve number (CN), area (A), and channel slope (SLPch) demonstrated strong correlations with SDR. SDR equations were developed by a combination of subwatershed parameters by referring to the correlation analysis. The area based power functional SDR developed in this study showed significant errors at the point right after entering major tributaries, because SDR was unrealistically reduced when the watershed area increased significantly. The SLPch-based power functional SDR also showed extraordinary values when the channel slope was gradual. The SDR equation that showed the highest value of the coefficient of determination also presented unrealistic changes in the sediment loads within a relatively short river distance. The SDR equation SDR=0.0003A0.198Rf/Lw1.167 was recommended for application to the Lake Imha watershed. Using this equation, sediment loads at the outlet of the Lake Imha watershed were calculated, and the HSPF parameters related to sediment in the uncalibrated subwatersheds were determined by referring to the sediment loads calculated with the SDR equation. |